Preparation of oxazolidone polymers in the presence of a magnesium halide/phosphine oxide complex

ABSTRACT

A process for preparing oxazolidones is provided by reacting an epoxide with an isocyanate in the presence of a catalytic amount of a magnesium halide/phosphine oxide complex. The reaction products thus produced can be used in a variety of applications. The polyoxazolidones obtained from polyepoxides and polyisocyanates can be used as liquid rubber materials, high temperature resistant resinous materials and the like.

. United States Patent Iseda et al.

[ Sept. 16, 1975 PREPARATION OF OXAZOLIDONE POLYMERS IN THE PRESENCE OF A MAGNESIUM HALIDE/PHOSPHINE OXIDE COMPLEX Inventors: Yutaka Iseda, Tachikawa; Motozumi Kitayama, Kodaira; Fumio Odaka, Kawagoe; Shiro Anzai, Higashi-Murayama, all of Japan Assignee: Bridgestone Tire Company Limited,

Tokyo, Japan Filed: Apr. 9, 1973 Appl. N0.: 349,176

Foreign Application Priority Data Apr. 14, 1972 Japan 47-36936 US. Cl. 260/77.5 R; 252/429 R; 260/2.5 AB; 260/2.5 AC; 260/775 AB; 260/77.5 AC; 260/551 P; 260/606.5 P

Int. Cl. 801,] 31/18; C08G 18/00; C08G 18/16; COSG 18/18 Field of Search... 260/77.5 R, 75 NE, 77.5 AB, 260/77.5 AC, 75 NC, 2.5 AC, 551 P, 606.5

lajs/ [56] References Cited UNITED STATES PATENTS 3,506,690 4/1970 Normant et a]. 260/551 P 3,687,897 8/1972 Clarke 260/77.5 AB 3,702,839 11/1972 Glasgow et al. 260/77.5 AB 3,721,650 3/1973 D'Alelio 260/77.5 R

Primary Examiner-H. S. Cockeram Attorney, Agent, or Firm-Stevens, Davis, Miller & Mosher [5 7] ABSTRACT 11 Claims, 1 Drawing Figure I I 1 I 1 l 03000 2500 2000 /800 I700 I500 I300 H00 900 700 PREPARATION OF OXAZOLIDONE POLYMERS IN THE PRESENCE OF A MAGNESIUM HALIDE/PHOSPHINE OXIDE COIWPLEX The present invention relates to a process for the preparation of oxazolidones. In one aspect it relates to a novel catalyst for use in the condensation addition of an epoxide with an isocyanate.

The preparation of oxazolidones by the condensation addition of the epoxides with isocyanates is described in the prior literature. For example, US Pat. No. 3,020,262 discloses such a reaction in which quaternary ammonium halides are utilized as the catalyst. However, the process is not entirely satisfactory since the reaction rate is slow as a result of the limited solubility of the catalyst and the reaction is accompanied with a side reaction, such as the isoeyanurate formation. Tetrahedron Letters, No. 12, p. 809 (1971) de scribes that the reaction rate is increased by the use of an alkali metal halide/phosphine oxide complex as a catalyst which is fairly soluble. However, the process is also not entirely satisfactory, since the reaction is also accompanied with a side reaction, such as the isocyanurate formation.

It is desired to cause only the desired reaction selectively without causing such side-reactions and further the improvement of reaction completeness, increase of reaction rate, decrease of the necessary amount of catalyst, a moderate pot life particularly required in bulk reaction, a solubility of catalyst are demanded. Some of them may be satisfied in the case of the well known catalysts but there is no catalyst which satisfies all these requirements.

An object of the present invention is to provide an improved process of the preparation of oxazolidones.

Another object of the invention is to provide a novel catalyst for the condensation addition of an epoxide with an isocyanate.

Other and further objects and advantages of the invention will become apparent to those skilled in the art upon consideration of the accompanying disclosure.

Broadly speaking, the process of this invention for preparing oxazolidones comprises reacting an epoxide with an isocyanate in the presence of a magnesium halide/phosphine oxide complex as the catalyst. It has been discovered that the catalyst of this invention is more selective and active than the prior art catalysts. Furthermore, the present catalyst is more soluble in the reactants, resulting into a more efficient utilization of the catalyst.

For a better understanding of the invention, reference is made to the accompanying drawing, in which:

The attached drawing shows infrared absorption spectrums of the resulting products but (a) shows the infrared absorption spectrum of the oxazolidone compound obtained in Example 2 and (b) and show those of the products in Comparative Examples 1 and 2, respectively.

The catalysts to be used in the present invention are phosphine oxide complexes of magnesium halide having a following general formula wherein X is a halogen atom, R R and R may be the same or different and are an aliphatic or aromatic hydrocarbon or an amine which is disubstituted by an ali phatic hydrocarbon, containing from one to 20, inclusive, of carbon atoms and n is any number withina range forming complex. As MgX mention may be made of MgCl MgBr and Mgl and among them MgCl is preferred and R O=P RZ 3 is, for example, hexamethylphosphoric triamide, tri-n butyl-phosphine oxide, triphenylphosphine oxide, tri-2-ethyl-hexylphosphine oxide, triisopropylphosphine oxide, and among them hexame- .thylphosphoric triamide, tri-n-butylphosphine oxide and triphenylphosphine oxide are preferable. n represents any numeral value within the range in which magnesium halide and phosphine oxide form a complex and is generally I, 2, 3 or 4. The phosphine oxide complexes of magnesium halide are, for example, hexamethylphosphoric triamide complex of magnesium chloride, tri-n-butylphosphine oxide complex of magnesium chloride, tri-phenylphosphine oxide complex of magne sium chloride, tri-2-ethylhexylphosphine oxide complex of magnesium chloride and the like and the same complexes of magnesium bromide and the same complexes of magnesium iodide. Among them phosphine oxide complex of magnesium chloride is preferable.

The isocyanate compounds to be used in the present invention are, for example. aliphatic isocyanates, such as ethyl isocyanate, n-butyl isocyanate, nhexyl isocyanate, hexamcthylene diisocyanate, aromatic isocyanates, such as phenyl isocyanate, tolyl isocyanate, naphthyl isocyanate, tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate, diphenylmethane-4,4- diisocyanate, diphenyldimethy[methane-4.4'- diisocyanate, phenylene-l,4-diisocyanate, 2,2',6,6- tetramethyldiphenylmethane-4.4'-diis0cyanate, diphenyl-4,4-diisocyanate, diphenyl.ethcr-4,4'-diisocyanate, S-chlorotolylene2,4-diisocyanate, 5-chlorotolylene- 2,6-diisocyanate, 2,4-diisopropylphenylene1,3- diisocyanate, m-xylene diisocyanate, p-xylene diisocyanate, a,a,zx'.a-tetramethyl-p-xylene diisocyanate, 2,5- dichloro-p-xylene diisocyanate, tetrachloro-pphenylene diisocyanate, tolylene-2,4-diisocyanate dimer, l,5-naphthalene diisocyanate, polymethylenepolyphenyl isocyanate, alicyclic isocyanates, such as cyclohexanel ,4-diisocyanate, dicyclohexylmethane4,4'-diisocyanate, l,2,3 ,4,5 .6- hexahydrodiphenylrnethane-4.4'diisocyanate and the like. lsocyanate terminated compounds obtained by reacting l mole of hydroxyl terminated compound, such as alcohol, glycol. triol with 2 mole of diisocyanate compounds and the like may be mentioned, The term glycols to be used herein are shown by the general formula OHR"-OH, for example, polyether series glycols, such as polypropylene oxide main chain type glycol, polytetrahydrofuran main chain type glycol, hydrocarbon main chain type glycols, such as polybutadiene glycol, polyisoprene glycol, butadiene/styrene copolymer glycol, butadiene/acrylonitrile copolymer glycol, isprene/styrene copolymer glycol, polyester main chain type glycol, polycarbonate main chain type gly col, aromatic series diols, such as bisphenol A, halogen substituted bisphenol A, hydroquinone, resorcinol and the like. The diisocyanate compounds are, for example, tolylene-Z,4-diisocyanate, tolylene-2,o -diisocyanate. diphenylmethane-4,4 -diisocyanate, diphenyldimethylmethane-4.,4diisocyanate, phenylenel .4- diisocyanate, 2,2,6,6-tetramethyldiphenylmethane- 4,4-diisocyanate, diphenyl-4,4'-diisocyanatc, diphenylether-4,4'-diisocyanatc, 5-chlorotolylene-2,4- diisocyanate, 5-chlorotolylene-2,6-diisocyanate, 2,4- diisopropylphenylene-l ,3-diisocyanate. m-xylene diisocyanate, p-xylene diisocyanate, a,a,oz',a-tetramethyl- .p-xylene diisocyanate, 2,5-dichloro-pxylene diisocya HO-R'-OH/epichlorohyrin condensate main chain structure type diepoxides (HO-R' OH shows the already mentioned glyeols), epoxy polyolefin, such partial epoxy compounds, of l,2-bond type polybutadiene, alicyclic epoxy compounds, such as dicyclopentadiene oxide, dipentene dioxide, vinylcyclohexene oxide, 3,4-epoxy-cyelohexylmethyl-3,4- epoxycyclohexane carboxylate, 3,4-epoxy-6-methylcyclohexyl-methyl-3 ',4 -epoxy-6 -methyl-cyclohexane carboxylate. novolak series epoxy compounds, such polyorthocresolformaldehyde poly( 2,3- epoxypropyl)ether, polyphenolformaldehyde poly( 2,3- epoxypropyl)ether and the like. Among them. polyepoxides having at least two oxirane groups are preferable in the production of polyoxazolidone and bisphenol A diglycidyl ether is particularly preferable.

According to the process of the present invention, oxazolidone compounds can be obtained in a good selectivity and a high yield from an isocyanate compound and an epoxy compound and it is possible to obtain various compounds from a low molecular weight compound to a high molecular weight compound by selecting the combination of an isocyanate compound and an epoxy compound. In order to produce high molecular weight polyoxazolidones, a combination of a diepoxide and a diisocyanate is preferable- Furthermore, in the high molecular weight compound it is possible to obtain from rubbery compounds having a high mechanical strength to rigid resinous compounds having an excellent heat resistance, As mentioned above, when bispheno'l A diglycidyl ether and a diisocyanatc capped prepolymer of a hydroxyl terminated polymer are selected as epoxide and isocyanate respectively, polyoxazolidone showing an excellent rubbery elasticity and having physical properties which have never been obtained, that is, a breakage strength of not less than 200 Kg/cm and an elongation atbreakage of not less than 40071, can be produced. This will become apparent from Examples and Comparative Examples.

The catalysts of the present invention have a high solubility and therefore the handling is simple and the reaction reproductivity is very excellent. Moreover, in the bulk reaction, since the pot life is moderate, the workability for the reaction system is very excellent.

In the process of the present invention, the mixture ratio of the isocyanate compound and the epoxy compound is varied depending upon the object and is not limited but when high molecular weight oxazolidone compounds are to be produced from a diisocyanate compound and a diepoxy compound, the equivalent ratio of isocyanate group/epoxy group is 40/60 to /35, preferably 45/55 to 55/45.

The reaction temperature is 20C to 250C, preferably C to 180C.

The reaction may be effected in a bulk system in the absence of solvent or effected in the presence of a solvent which does not influence upon the reaction. Such solvents are polar solvents, such as aliphatic hydrocarbons, ali cyclic hydrocarbons, aromatic hydrocarbons, halides, nitro compounds, ethers, dimethylformamides, dimethylsulfoxides thereof. Among them, benzene, toluene, xylene, o-dichlorobenzene, chlorobenzene, bromobenzene, tetralin, decalin, mesitylene, di-n-butyl ether, diisobutyl ether, diphenyl ether, nitrobenzene, dimethylformamide, dimethylsulfoxide and the like are preferable. A mold reaction system wherein no solvent bulk reaction is applied, can be advantageously adopted and in this case various features of the magnesium catalyst can be developed. For example, the product of a high molecular weight oxazolidone compound can be directly produced in a mold reaction system from a diepoxy compound and a diisocyanate compound and in this case, the necessary amount of the catalyst may be very small and the catalyst dissolves homogeneously in the reaction system and the pot life in the mold is sufficient and when the temperature is raised to an adequate reaction temperature, the reaction is completed in a short time and a molded product composed of a high molecular weight oxazolidone in a conversion rate of can be produced.

The addition order is not particularly limited but in the case of bulk reaction, it is preferable in order to develop various features of the catalyst to dissolve the catalyst in the presence of an epoxy compound. The amount of the catalyst used varies depending upon the object and is not particularly limited and in general it is 0.05 to 10 mol percent, preferably 0.125 to 1.0 mol percent based on the total amount of isocyanate group equivalent and epoxy group equivalent.

The reaction system is preferred to be substantially anhydrous but the oxazolidone producing reaction is not completely stopped by admixture of a very small amount of water.

The reaction system may be under a dried air atmosphere but is preferred to be under a dried inert gas. such as nitrogen gas or argon gas.

The pressure condition in the reaction system is not particularly limited.

When the process of the present invention is applied to the production of a product composed of a high molecular weight oxazolidone compound from a low molecular weight epoxy compound and a low molecular weight isocyanate compound by a mold reaction system in a bulk reaction. various processes are adopted depending upon the object and the starting materials to be used. For example, pour press molding. transfer molding, injection molding,'rotation molding, centrifugal casting, vacuum casting. plastic rubber process are cited. 1

Thus, various useful oxazolidone compounds can be obtained by the method of the present invention and the high .molecularweight compoundsjcan be applied for motorcar parts, buffer materials. medical materials, laminate materials, coating materials, heat resistant resin materials, foam materials, long lasting medicines, long lasting pesticides and the like and further they are foamed and used for various cushion materials, heat insulating materials and building materials. The low molecular weight compounds can be used for muscle relaxing agent. fungicides. plant growth accelerator, an

agent for preventing Puccinia triticina ERlKS, food ad ditives, extraction solvents for petroleum, and plasticizers. I i

The following examples are given for the purpose of illustration of this invention and are not intended as limitations thereof.

EXAMPLE 1 Preparationof the catalyst into an egg-plant type flask of 200 ml capacity were charged 1.43 g of magnesium chloride dried at 100C for 3 days under vacuum, 5.38 g of hexamethylphosphoric triamide purified byra reduced pressure distillation (98 to 100C/6 mm Hg) and 75 ml of benzenepurifled by a distillation after dehydrationthrough Molecular Sieves 4A, and the resulting mixture was stirred and dissolved. The solution was subjected to a freezedrying under a reduced pressure to obtain a white powdery hexamethylphosphoric triamide complex of magnesium chloride. Other catalyst systems of the present invention can be produced in the same procedure as described above.

EXAMPLE 2 Into a separable flask equipped with a stirrer and a 7 three way stop-cock communicated to a vacuum line and a nitrogen line were charged 8.42 g of an epoxy resin having a molecular weight of about 380 and an epoxy equivalent of 184 to 194 (made by Shell Co., trademark: Epikote No. 828) and 0.12 g of the catalyst prepared in Example 1, and the resulting mixture was stirred and deaired at 100C under a reduced pressure of 1 mm Hg. Whenthe mixture was stirred for about 5 minutes. the catalyst was homogeneously. dissolved in the epoxy resin. After the reaction system was brought up to atmospheric pressure with gaseous nitrogen, 55 g of a diisocyanate type prepolyrnenhaving iso'eyanate groups at both terminals and having an average molecular weight of about 2,000 and an isocyanate equivalent of about 1,000 (made by Du Pont Co., trademark: Adiprene L-100), was charged into the flask (the equivalent ratio of isocyanate group/epoxy group is 55/45). The resulting mixture was stirred and deaired at 60C for about 5 minutes under a reduced pressure of 1 mm Hg to obtain a light yellow, transparent homolow, transparent. high molecular .weight rubbery slab sheet containing nofoam. In the infrared absorption spectrum of the sheet, both of the characteristic absorptions drawinglisocyanate group at 2,240 cm and of epoxy group at about 900 cm were not observed, while a characteristic absorption of oxazolidone group was observed at 1,750 em, but a characteristic absorption of isocya'riurate ring at 1,700 cmwas not observed [refer to (a) on the drawing]. As the result of the above infrared absorption spectrum analysis, it was confirmed that the reaction proceeded in a high selectivity and was completed in 100% conversion and a high molecular weight oxazolidone compound was formed. When the reaction at 150C was traced with infrared absorption spectrum analysis, it was confirmed that the reaction was com- Breakage strength- (hereinafter abridged as T 302 Kg/cm Elongation at breakage (herein' :tcr abridged as E 506% Initial modulus of elasticity (hereinafter abridged as E) i Kg/cm" 7: Modulus (hereinafter abridged as um) Z) Kg/cm 300% Modulus 55 Kg/erii (hereinafter abridged as M As described above, according to the processof the present invention, the reaction for producing oxazolidone compounds proceeds in a high selectivity and is completed in avery short time in the presence of a very small amount of catalyst bythe reaction in mold, and as the result molded articles having an'excellent mechanicalstrength as a rubbery elastorner can be ob tained, 1 v

' COMPARATIVE EXAMPLE 1" A hexamethylphosphoric triamide complex of lith ium chloride, which is known as an excellent catalyst among conventional catalysts, was prepared in the following manner 1n the same manner as described in Example l, 65 ml of purified benzene, 2.12 g of purified lithium chloride 13.8 g ofipurifled hexamethy l phosphoric triamide were charged into an egg-plant type flask of 200 ml capacity, and the resulting mixture was stirred and dissolved. Then, the resulting solution was subjected to a freeze-drying under a reduced pressure to obtain a white powdery hexamethylphosphoric triamide complex of lithium chloride.

Then, in the same manner as described in Example 2, 7.1 g of Epikote No. 828, 0.044 g of the above obtained lithium catalyst (this amount corresponds to the same molar concentration as the molar concentration of the magnesium catalyst in Example 2) and 40 g of Adiprene .L-100 were treated, poured into a mold and left to stand for 5hours in "an oven kept at C to obtain a rubbery slab sheet.

7 8 Physical properties of the resulting sheet measured in EX MP the same manner as descr1bed in Example 2 were as fol- The procedure described in Example 2 was repeated lows except that the oven temperature and the time for keeping the mold in the oven were varied, to obtain light yellow. transparent rubbery slab sheets.

T 77 lx'g/cm Conditions different from those 1n Example 2 and ?g 2 physical properties of the resulting sheets are shown in the following Table 1.

Table 1 Physical properties of slab sheet ()ven Example temper Time Not ature in oven T [5,, li M M WC) (hr.) (Kg/en?) (/f) (Kg/em") (Kg/GU1 (Kg/c111 3 150 1 269 502 64 24 52 4 3 2X3 515 s3 27 56 5 229 522 66 24 43 6 256 553 64 23 42 7 5 503 45 1) 32 x 5 22*) 514 62 25 44 9 170 5 1x2 4ss 7s 25 57 As seen from the comparison of the physical proper- EXAMPLES 10-12 s 2 z :l :5 the i i ig l z l md lf 2S The procedure described in Example 2 was repeated, r Xdlmp e b3 g g j cm except that the amounts of Epikote No. 828 and Adii w l i e O tame y prene L-lOO, the oven temperature and the time for vgntlona cata yst. can e obtained by the catalyst of keeping the mold in the ovfin were varied to Obtain t e present light yellow, transparent rubbery slab sheets.

I w Conditions different from those in Example 2 and Moreover, in the infrared absorption spectrum of the physical properties of the resulting sheets are shown in slab sheet obtained by using a conventional lithium sethe following Table 2.

Table 2 Equivalent ratio of Oven Physical properties of slab sheet Example lipikote Adiprcne isoeyanate lemper- Time Nov No. 828 l.-l()ll group ature in oven T E E M166 M (g) (g) epoxy group (hrv) (Kg/cnfi) (71) (Kg/cm) (Kg/em") (Kg/cm") ries catalyst. the characteristic absorption of isocyanu- EXAMPLES l3 and 14 rate rin at l.7()() cm was observed i t 1 L 5 1 7 I n dddlmn thlt lhe procedure described In Examples l and 2 was ooxzz I 1 5 t t dr ggnup 0 to (b) on repeated. except that the amounts of magneslum ehlo lll t m H t p?! groups was mu r1de (Mg(l and hexamethylphosphoric triannde a t .v.

y b mm V by Pmduu' (abndged as HMPA) and the amount of catalyst to be so used were varied, to obtain light yellow. transparent rubbery slab sheets. As seen from the companson of the infrared absorp- C dition different from those in Example 2 and non spectra of the sheets obtained in Example 2 and h i l erties of the resulting sheets are shown in Comparative Example 1, oxazolidone compounds conthe following Table 3.

Table 3 Physical properties of slab sheet Example Mg(l. HMPA Amount of No. (g) (g) catalyst T Ii E M M (g) (Kg/cm") ("l (Kglcm (Kg/c111 (Kg/enf") 13 1.43 2 h) 0.07 342 501 12s 41 79 14 1.43 10.76 0.21 3. 4s 542 104 36 63 taining a very small amount of by-products. which can- 65 EXAMPLES l5-l7 not be obtained b a conventional C'ltll st. can be ob- 4 l y Catalysts were prepared in the exactly same manner t-i* t v aned by the catilyst of he present lmention as described m EXumplc 1. except that tri n Table 4 nate compound:

ln a separable flask equipped with a stirrer and a three way stop-cock communicated to a vacuum line and a nitrogen line, polytetrahydrofuran main chain type glycol having a molecular weight of 3,510 was stirred at about 80C for several hours under a reduced pressure of 1 mm Hg to remove Water. Then, tolylene- 2,4diisocyanate was added to the glycol at about 70C at one time in a ratio of 350 g of the diisocyanate per 10 3.150 g of the glycol. The resulting mixture was stirred Physical properties of slab sheet Example MgCl Ligand Name of Amount of No. (g) (g) ligand catalyst T E E M M (g) (Kg/c111 (/r) (Kg/cm") (Kg/cm") (Kg/ch1 I 5 1.43 9.83 TBPO 0.2 346 520 7) 35 59 16 1.43 3.54 TEHPO (J, l 3 ll7 410 52 ll 5] 17 1.43 I".5l) TPPO 0.24 272 458 8] 29 7| the following Table 5.

for about l hour and further at 80C for about 8 hours under nitrogen atmosphere, and left to stand for one night. The amount of the remaining isocyanate groups in the reaction product was analyzed with the amine equivalent method to confirm the formation of a prepolymer having isocyanate groups at both terminals and having an isocyanate equivalent of 2,030.

(B) In the same procedure as described in Example 2, 4.4 g of Epikote No. 828, 0.1 l g of the catalyst pre pared in Example 1 and 53.8 g of the above obtained diisocyanatc type prepolymer (the equivalent ratio of Table 5 ()vcn Physical properties of slab sheet Example Hydrous tempera Time No. catalyst ture in oven T,, E E m, m

(g) (C) (hr.) (Kg/em ("/1) (Kg/cm) (Kg/m (Kg/cm l8 0,13 130 162 448 59 24 4) 19 0.13 I50 5 234 484 66 26 54 20 0. l 3 170 5 l0] 4H 57 22 As seen from Table 5, even when a catalyst system containing a small amount of water is used, the reaction proceeds.

EXAMPLES 21 and 22 The procedure described in Example 2 was repeated, except that the amount of catalyst to be used and the heating temperature of the mold in the oven were varied, to obtain light yellow, transparent rubbery slab sheets.

Conditions different from those in Example 2 and physical properties of the resulting sheets are shown in isocyanate group/epoxy group is 53/47) were treated, poured into a mold and left to stand for 5 hours in an oven kept at 150C to. obtain a rubbery slab sheet.

Physical properties of the resulting sheet were as follows.

T 222 Kg/cm" E 5407:

E '99 Kgjcm M 38 Kg/cm 55 the following Table 6. The infrared absorption spectrum in the range of Table 6 Example Amount of Equivalent ratio Oven Time Physical properties of slab sheet No. catalyst of calalystfl isotemperain oven (g) cyanatc group ture (hr.) T,, F. E M M epoxy group) (C) (Kg/cm") (71) (Kg/cm (Kg/cm") (Kg/cm'-') II 0.06 l/XUU l5() 5 259 5 I0 64 25 49 I: (1.24 l/ZUU l3() 5 227 522 5U 19 3] EXAMPLE 23 1,800 cm" to 1,600 cm of the resulting sheet was ex- (A) Preparation of the prepolymer having isocyanate groups at both terminals from a glycol and a diisocyaactly same as the spectrum of the sheet obtained in Example 2 shown at (a) on the drawing (i.e., the charac- .ii teristic absorption of oxazolidone group was observed at 1,750 em, but the characteristic absorption of isocyanurate ring at 1,700 cm" wasnot observed), and furthenboth of the characteristic absorptionsof isoeyanate group at 2,240 crri' and of epoxy group at about 900 cm were not at all observed. ltwas confirmed from this fact that the reaction proeeeded in a high selectivity and was completed, and a high molecular weight oxazolidone compound was formed. L

COMPARATIVE EXAMPLE 2 A polyoxazolidone was prepared in the following manner by using tri-n-propylethylammonium iodide,

which is known as a fairly active catalyst among conventional catalysts.

In the same procedure as described in Example 23, 0.075 g of the above described quaternary ammonium salt catalyst was added to 7.1 g of Epikote No. 828, and the resulting mixture was stirred and mixed at 60C to 70C under a reduced pressure. Then, 62 g of the diisocyanate type prepolymer obtained in Example 23(A) In the infrared absorption spectrum of the resulting slab sheet, the characteristic absorption of isoeyanuratering at l .700 cm was observed in addition to that of oxazolidone group at l .750 cm (refer to on the drawing). This shows that isocyanate groups were mutually reacted to form a'cyclizedtrimer as'a by-product. As seen from the comparison of Example 23 and Comparative Example 2, molded articles containing a very small amount of by-products and having excellent physical properties, which cannot be obtained by a conventional catalyst, can be obtained by the catalyst of the present invention.

EXAMPLES 2427 The procedure described in Example 23(8) was repeated, except that the amounts of Epikote No. 828 and the diisocyanate type prepolymer were varied, to obtain rubbery slab sheets.

Conditions different from those in Example 23(8) and physical properties of the resulting sheets are shown in the following Table 7.

was added thereto, and the resulting mixture was stirred at 60C to 70C under a reduced pressure to effect mixing and deairing simultaneously. [When the mixture was treated at the same temperature as that of Example 23(8), the treated mixture had a very short pot life, and gelled in a very short period of time, and it was often impossible to pour the treated mixture] Then, the reaction system was brought up to atmo spherie pressure with gaseous nitrogen, and the above treated mixture was poured into a mold previously heated ZIT'6OOC ti) 70C,and the mold was left to stand EXAMPLES 28-32 for 5 hours in an oven kept atl70C to permit a reac- 45 828 was varied. t o tain rubbery l Sheets. tion-"to proceed and to obtain a rubbery slab sheet. Conditions different from those in Example 2 (When the oven tem erature is 150C. the reaction and physical properties of the resulting sheets are rate is very low.) shown in the following Table 8.

Table 8 Equivalent Physical properties ratio of of slab sheet Example lpikote Prepolymer isoeyanate No. No. N28 (M\\:(ll)(ll group 'l E E M (g) (g) epoxy group (Kg/cm") ('4) (Kg/e111") (Kg/cm) Is 955 (10.: 49 51 ms 522 72 5s 2w 9.2 03.0 51 is: 550 m 44 30 8.8 05.] 53/47 171 482 (13 57 .11 s4 07.5 55 :05 53a 3 53 .1: so 70.0 57 41 15: 501) s7 Physical properties of the resulting sheet were as fol- EXAMPLE 33 lows.

The procedure described in Example 25 was re- T p7 K I peated. except that 2.6 g of tolylcne-2,4-diisoeyanate n g/ I p 1;, and 51.7 g ot the prepolymer prepared in Example l1 3X Kg/Cl11 23(A) were used as diisoeyanate compounds and mm 9 kg/eml0.-l3 g of Epikote No. 828 was used as diepoxy com- 157 Kg/cm E 612 Kg/em Mano 133 a EXAMPLE 34 In a separable flask of 300 ml capacity, 0.16 g of the hexamethylphosphoric triamide complex of magnesium chloride prepared in Example I and l 1.0 g of Epikote No. 828 were mixed at 90C under vacuum while stirring to prepare a homogeneous solution. After the reaction system was brought up to atmospheric pressure with gaseous nitrogen, 50 g of Adiprene L- l was added to the solution, and theresulting mixturewas again stirred and deaired under .vacuum. After the reaction system was brought up to atmospheric pressure with gaseous nitrogen, .15 ml oftolylene-2,4- diisocyanate was added to the above deaired mixture, and then the resulting mixture was again deaired at room temperature under a reduced. pressure, and poured into a chromium-plated stainless steel mold having a depth of 2 mm, which had previously been heated at about 70C. The mold was covered with a glass plate and left to stand for 5 hours in an oven kept at 150C to obtain a light yellow, transparent rubbery slab sheet. Ring-shaped test samples having an inner diameter of 25 mm and a width of 2 mm were punched out from the sheet, and physical properties of the sheet were measured with respect to the samples by means of an Instron tension tester to obtain the following results.

n 303 Kg/cm" I E 506% E 167 Kg/cm M 46 Kg/cm M 90 Kg/cm Further, the sheet had a J 18 hardness of 80 and a melting point of 240C to 250C.

EXAMPLE 35 The procedure described in Example 34 was repeated, except that 0.22 g of the catalyst, 14.9 g of Epikote No. 828, 40 g of Adiprene L-l00 and 4.0 ml of tolyylene2,4-diisocyanate were used, to obtain a light yellow, transparent rigid elastic slab sheet. Physical properties of the sheet were as follows.

'I',, 300 Kg/cm E 340% E 887 Kg/cm Further, the sheet had a .115 hardness of 91 and a melting point of higher than 300C.

The procedure described in Example 34 was repeated, except that 0.26 g of-the catalyst,..l 7.6 g of Epikote No.5828, 30 g oflAdiprene L- LOO and 5 .9 ml of tolylene-2,4-diisocyanate were used, to obtain -a light yellow, transparent elastic resinous'slabsheet. Physical properties of the sheet were as follows. l

Further, the sheet had a JlS maimed 93; and a melt kote No. 828, 20 g of Adiprene t-iooahii' 1 1.9 rnlof tolylene 2,4-diisocyanate were used, to obtain a light yellow, transparent resinous slab sheet. The sheet had a J [S hardness of 95 and a melting point of higher than 300C and didriot substantially change its shape at 300C. Therefore, the sheetlwzis a resin haying andem Cellent heat resistance. V I i Y EXAMPLE 38 The procedure described in Example l 34 was repeated, except that 0. l 2 g ofcatalyst, 7.8 g of DER No. 736 (trademark of a polypropylene oxide main chain type diepoxide made by Dow Co.) instead of Epikote No. 828 and 50 g of Adiprene L-l00 were used, but tolylene-2,4-diisocyanate was not used, to obtain a light yellow, transparent rubbery slab sheet.

EXAMPLE 39 The procedure described in Example 34 was repeated, except that 0.12 g of the catalyst, 2.5 g of Chissonox No. 206 (trademark of vinylcyclohexene diepoxide made by ChissoUCC Co.) instead of Epikote No. 828 and 40 g of Adiprene L-l00 were used, but tolyelen-2,4-diisocyanate was not used, to obtain a light yellow, transparent flexible slab sheet.

What is claimed is:

l. A process for preparing an oxazolidone polymer which comprises reacting a polyisocyanate with a poly epoxide, the equivalent ratio of isocyanate groups of said polyisocyanate to epoxide groups of said polyepoxide being 40/60 to 65/35 at a temperature of 20C to 250C in the presence of a magnesium halide/phosphine oxide complex having the following formula in which X is a halogen atom, R R and R are selected from the group consisting of an aliphatic and aromatic hydrocarbon and an amine which is disubstituted by an aliphatic hydrocarbon, containing from one to 20, inclusive, carbon atoms; :1 is l, 2, 3 or 4, the amount of said magnesium halide/phosphine oxide complex being ()()5 to mol percent of the amount of said polyepoxide and said polyisocyanate.

2. A process according to claim 1, in which said magnesium halide is magnesium chloride.

3. A process according to claim 1, in which said phosphine oxide is any one of hexamethylphosphoric triamide, tri-n-butyl phosphine oxide and triphenyl phosphine oxide.

4. A process according to claim 1, in which said magnesium halide/phosphine oxide complex is a complex compound selected from the group consisting of magnesium chloride/hexamethylphosphoric triamide complex, magnesium chloride/tri-n-butylphosphine oxide complex, magnesium chloride/tri-n-ethylhexylphosphine oxide complex, and magnesium chloride/triphenylphosphine oxide complex.

5. A process according to claim 1, in which said polyisocyanate has at least two isocyanate groups.

6. A process according to claim 5, in which said polyisocyanate is a diisocyanate capped prepolymer of a hydroxyl terminated polymer wherein said diisocyanate is an'aromatic diisocyanate.

7. A process according to claim 6, in which said diiso cyanatc is tolylene diisocyanate.

8. A process according to claim I, in which said polyepoxide has at least two oxirane groups.

9. A process according to claim 1, in which said polyepoxide is a diepoxide and said polyisocyanate is a diisocyanate.

10. A process according to claim 1, in which said polyepoxide'is a bisphenol A diglycidyl ether.

11. Polyoxazolidone polymers having a breakage in which X is a halogen atom, R R and R are selected from the group consisting of an aliphatic and aromatic hydrocarbon and an amine which is disubstituted by an aliphatic'hydrocarbon, containing from one to 20, inclusive"; carbon atoms; 11 is l, 2, 3 or 4, the amount of said magnesium halide/phosphine oxide complex being 0.05 to 10 mol percent of the amount of said polyepoxide and said polyisocyanate. 

1. A PROCESS FOR PREPARING AN OXAZOLIDONE POLYMER WHICH COMPRISES REACTING A POLYISOCYANATE WITH A POLYEPOXIDE, THE EQUIVALENT RATIO OF ISOCYANATE GROUPS OF SAID POLYISOCYANATE TO EPOXIDE GROUPS OF SAID POLYEPOXIDE BEING 40/60 TO 65/35 AT A TEMPERATURE OF 20*C TO 250*C IN THE PRESENCE OF A MAGNESIUM HALIDE/PHOSPHINE OXIDE COMPLEX HAVING THE FOLLOWING FORMULA
 2. A process according to claim 1, in which said magnesium halide is magnesium chloride.
 3. A process according to claim 1, in which said phosphine oxide is any one of hexamethylphosphoric triamide, tri-n-butyl phosphine oxide and triphenyl phosphine oxide.
 4. A process according to claim 1, in which said magnesium halide/phosphine oxide complex is a complex compound selected from the group consisting of magnesium chloride/hexamethylphosphoric triamide complex, magnesium chloride/tri-n-butylphosphine oxide complex, magnesium chloride/tri-n-ethylhexylphosphine oxide complex, and magnesium chloride/triphenylphosphine oxide complex.
 5. A process according to claim 1, in which said polyisocyanate has at least two isocyanate groups.
 6. A process according to claim 5, in which said polyisocyanate is a diisocyanate capped prepolymer of a hydroxyl terminated polymer wherein said diisocyanate is an aromatic diisocyanate.
 7. A process according to claim 6, in which said Diisocyanate is tolylene diisocyanate.
 8. A process according to claim 1, in which said polyepoxide has at least two oxirane groups.
 9. A process according to claim 1, in which said polyepoxide is a diepoxide and said polyisocyanate is a diisocyanate.
 10. A process according to claim 1, in which said polyepoxide is a bisphenol A diglycidyl ether.
 11. POLYOXAZOLIDONE POLYMERS HAVING A BREAKAGE STRENGTH OF NOT LESS THAN 200 KG/CM2 AND AN ELONGATION AT BREAKAE OF NOT LESS THAN 400% PREPARED BY REACTING (A) BISPHENOL A DIGLYCIDYL ETHER AND (B) TOLYLENE DIISOCYANATE CAPPED PREPOLYMER OF HYDROXYL TERMINATED POLYETHER GLYCOL, THE EQUIVALENT RATIO OF ISOCYANATE GROUPS OF SAID TOLYLENE DIISOCYANATE CAPPED PREPOLYMER (B) TO EPOXIDE GROUPS OF SAID BISPHENOL A DIGLYCIDYL ETHER (A) BEING 40/60 TO 65/53, AT A TEMPERATURE OF 20*-250*C IN THE PRESENCE OF A MAGNESIUM HALIDE/PHOSPHINE OXIDE COMPLEX HAVING THE FOLLOWING FORMULA MGX2 . (O=P(-R2)(-R3)-R1)N IN WHICH X IS A HALOGEN ATOM, R1, R2 AND R3 ARE SELECTED FROM THE GROUP CONSISTING OF AN ALIPHATIC AND AROMATIC HYDROCARBON AND AN AMINE WHICH IS DISUBSTITUTED BY AN ALIPHATIC HYDROCARBON, CONTAINING FROM ONE TO 20, INCLUSIVE, CARBON ATOMS, N IS 1, 2, 3 OR 4, THE AMOUNT OF SAID MAGNESIUM HALIDE/PHOSPHINE OXIDE COMPLEX BEING 0.05 TO 10 MOL PERCENT OF THE AMOUNT OF SAID POLYEPOXIDE AND SAID POLYISOCYANATE. 